Color Phase & Color Gain at DVinfo.net

Steve Graham · March 2nd, 2008, 12:27 PM

Can someone help me understand exactly what these two preset customizations do (adjusting up or down results and general influence on the film). Thanks.

Chris Hurd · March 2nd, 2008, 01:06 PM

In simple terms (what better terms are there than simplest), Color Gain is a saturation control. The higher the value, the more saturated the colors are. The lower the value, the less color there is overall. Dial it all the way down and you're shooting in monochrome black and white.

Color Phase is basically an overall hue control. Positive values push more toward magenta while negative values push toward green (wait, should that be hue or tint? I can't think straight on weekends, or at least not after a Saturday night).

See http://www.dvinfo.net/conf/showthread.php?t=69784 for more help,

Steve Graham · March 3rd, 2008, 01:01 PM

Exactly what I needed. Appreciate it.

A. J. deLange · March 5th, 2008, 06:52 AM

If you were to hook up your camera to a vector scope or use the one in FCP or in any of the other editing packages and twiddle these controls you would see the following effects. An increase in gain would cause the dots on the vector scope to move away from the center towards the edges. The center represents neutral colors (grays, black, white), the region near the center pastels and the circle pure (highly saturated) colors. The gain control is thus, as Chris noted, a saturation control. Changing the phase control would cause the picture on the vectorscope to rotate. As the pure colors are arranged around the circle the phase control is a hue control.

The terminology is left over from the old days of TV in which the color information was broadcast on a color subcarrier. In the early days every set had a control (usually labeled "color" or something like that) that varied the amplitude of the chroma signal and another (usually labeled "hue") which varied the phase of the oscillator (derived from the color burst) which fed the color demodulators. One had to constantly twiddle these controls to get a decent color picture. In today's digital world the gain controls the amplitude of the two color difference signals and phase adjustments cause a so called "unitary rotation" to be applied to them. The results are the same as in the analogue days but the operations are now done mathematically on the 1's and 0's that represent the signals rather than by changing the gains and phase responses of analogue networks.

March 2nd, 2008, 12:27 PM	#1
Steve Graham Regular Crew Join Date: Dec 2007 Location: Chicago IL Posts: 30	Color Phase & Color Gain Can someone help me understand exactly what these two preset customizations do (adjusting up or down results and general influence on the film). Thanks.

March 2nd, 2008, 01:06 PM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	In simple terms (what better terms are there than simplest), Color Gain is a saturation control. The higher the value, the more saturated the colors are. The lower the value, the less color there is overall. Dial it all the way down and you're shooting in monochrome black and white. Color Phase is basically an overall hue control. Positive values push more toward magenta while negative values push toward green (wait, should that be hue or tint? I can't think straight on weekends, or at least not after a Saturday night). See http://www.dvinfo.net/conf/showthread.php?t=69784 for more help, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

March 3rd, 2008, 01:01 PM	#3
Steve Graham Regular Crew Join Date: Dec 2007 Location: Chicago IL Posts: 30	Thank you Exactly what I needed. Appreciate it.

March 5th, 2008, 06:52 AM	#4
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	If you were to hook up your camera to a vector scope or use the one in FCP or in any of the other editing packages and twiddle these controls you would see the following effects. An increase in gain would cause the dots on the vector scope to move away from the center towards the edges. The center represents neutral colors (grays, black, white), the region near the center pastels and the circle pure (highly saturated) colors. The gain control is thus, as Chris noted, a saturation control. Changing the phase control would cause the picture on the vectorscope to rotate. As the pure colors are arranged around the circle the phase control is a hue control. The terminology is left over from the old days of TV in which the color information was broadcast on a color subcarrier. In the early days every set had a control (usually labeled "color" or something like that) that varied the amplitude of the chroma signal and another (usually labeled "hue") which varied the phase of the oscillator (derived from the color burst) which fed the color demodulators. One had to constantly twiddle these controls to get a decent color picture. In today's digital world the gain controls the amplitude of the two color difference signals and phase adjustments cause a so called "unitary rotation" to be applied to them. The results are the same as in the analogue days but the operations are now done mathematically on the 1's and 0's that represent the signals rather than by changing the gains and phase responses of analogue networks.